Molding die and means for removing molded articles therefrom



July 23, 1946. gGRONEMEYER 2,404,631

MOLDING DIE AND MEANS FOR REMOVING MOLDED ARTICLES THEREFROM Filed Feb. 9, 1944 4 Sheets-Sheet l INVENTOR [ma Geo/v5: YER

ATTO R NEY i y 1946- E. GRONEMEYQER 2,404,631

MOLDING DIE AND MEANS FOR REMOVING MOLDED ARTICLES THEREFROM Fil ed Feb. 9, 1944 4 Sheets-Shet 2 glllllll"IlillINIHHIHIIUIIIWIillWlllHllWIWIIWINHH ummmuw lllll my w y ii Hu ATTORN EYS 4 Sheets-Sheet 3 E. GRONEMEYER Fil ed Feb. 9, -1944 s 2 A 0 T Y 4 M 5 m v N M T. Irvin-l. i wT .l E A u FL... N .ZL FL m m 6 MOLDING DIE AND MEANS FOR REMOVING MOLDED ARTICLES THEREFROM July 23 23, 1946. E. GRQNEMEYER 9 1 3 MOLDING DIE AND MEANS FOR REMOVING MOLDED ARTICLES THEREFROM Filed Fer 5. 9, 1944 4 Sheets-Sheet 4 me ll s N R E 0 v T n em B H w 2 m Patented July 23, 1946 MOLDING DIE AND MEANS FOR REMOVING MOLDED ARTICLES THEREFR-OM Erich Gronemeyer, Pompton Plains, N. J assignor to Mack Molding Company, Incorporated, Wayne, N. J., a corporation of New Jersey 7 Application February 9, 1944', SerialNo. 521,669

6 Claims. (Cl. 18-16) UNITED LSTATES PATENT orrrcEifV This invention relates to dies for forming threaded articles of thermo-plastic or thermo-setting materials and more particularly to means for removing the articles from the dies and it is an object of this invention to provide means for rapidly and simultaneously removing a plurality of molded threaded articles from the dies by which the articles are made and it is a further object to provide a construction of the dies for forming the articles and the means for removing the articles from the dies such that the time required for molding and'setting the articles is reduced to a ,minimumand without danger of the articles being distorted or deformed before or during removal from the dies.

In the drawings in which the invention is shown applied to dies for the molding of interior.- ly threaded container caps:

Fig. 1 is a broken top plan view of dies and means for removing molded caps from the dies constructed in accordance with this invention;

Fig. 2 is a View, partly in side elevation and partly in vertical section, as on line 2-2 of Fig.

1, of the apparatus shown in Fig. 1;

.Fig. 3 is a partial top plan view of the dies shown in Fig. 1, drawn to a larger scale and having parts broken away to show other parts more clearly;

Fig. 4 is a vertical sectional view taken as on line 44 of Fig. 3, showing the dies separated and with molding material in the lower die preparatory to a molding operation;

Fig. 5 is a view similar to Fig. 4 showing the dies pressed together for the molding operation;

Fig. 6 is a view similar to Fig. 4 showing the dies separated during the operation of removing the cap from the upper die;

Fig. 7 is a plan view showing the interior of a cap molded by the dies shown in Figs. 1 to 6;

Fig. 8 is a bottom plan view of a portion'of the upperdie which molds part of the inner face of the cap;

Fig. 9 is a sectional View of Fig. 4; and

Figs. 10 and 11 are partial vertical sectional taken as on line 9--9 views showing dies of modified constructions.

In the drawings the invention is shown in connection with a lower die holder I secured to a lower plate 2 and an upp r die holder 4 secured to an upper plate 6 but spaced therefrom by a filler plate 8. The die holders are shown as being Iormed with cavities for only a small number of dies but a larger number of cavitiesmay be provided. In each cavity in the lower die holder I there is placed adie l0 which is recessed to receive th upper die'and is held in position by cooperating shoulders on the die and the lower die holder I. The lower die holder 1 and lower plate 2 are formed with the usual guide openings l2 to receive the usual guide pins l4 which are secured in openings in the top plate 6 by a cover plate l6 and project from the top die holder 4 so as to be engaged in the openings l2. I

In the upper die holder 4 there are formed cavities corresponding to the cavities of the lower die holder l and mounted in each cavity is a bushing l8 secured against rotation bya key 20, the bushing and die holder being formed with cooperating shoulders, as at 22, which serve to position the bushing in the die holder. Rotatably mounted in each bushing 18 is an upper or male die 24, which is shaped, as at 24!, to form an internal thread on the molded cap. The die 24 is centrally bored to freely receive a pin 26 and recessed as at 242 to receive the tapered end piece 262 of the pin. The die 24 has its upper surface recessed to receive a projecting portion of a gear 28 which is journaled in a'bushing 30 fixed in an opening in the filler plate 8 by a key 32. A key 34 secures thedie 24 for rotation with the gear 28.

Slidably mounted in grooves in the filler platev B and engaging with the gears .28 are the rack bars 36 which project beyond the fillerplate 8 and are connected to a cross head 38. The cross head 38 is mounted for reciprocation in guides 40 which are secured to opposite sides of the top plate 6 and are joined adjacent'their outer ends by cross members 42; The members 42 also serve to support a cylinder 44 in which is a, piston (not shown) connected by a rod 46 tothe-cross head 38 to operate the same. A suitable fluid operating medium is supplied to the cylinder 44 to operate the piston therein and thus reciprocate the rack bars 36 and rotate the gears 28 and dies 24. r

The pin 26 projects into an opening in the top plate 6 and adjacent its upper end the pin 26 is provided with an opening in which is fitted a small pin 25 which projects on both sides of the pin 26 and engages in grooves I! cut in the wall of the opening in the top plate 6 to prevent the pin 26 from turning. A spring [9 confined between the top of the pin 26 and the cover plate I6 biase the pin 26 to its lowest position and a washer 2! secured between the bushing 36 and the top plate 6 engages the pin 25 to limit. the downward movement of the pin 26. At its lower end the bodyof the pin 26 is formed with a re-.

duced end portion 26f which. fits "a recess ina tapered end piece 262. the recess into which it fits in the end piece 262, may be angular in shape to prevent relative rota- The end portion 26l and The outer face of the end piece 262 is formed with a plurality of spaced curved projections 264 adjacent its outer edge designed to form recesses 50 in the inner face of the cap 52 and to. interlock therewith to prevent rotation of the cap. 52 with respect to the end piece 262.

In practice, the lower and upper plates Z' and 6. p

are secured to the lower and upper heads respectively of a press, the lower h'ead preferably beingoperable to raise and lower the lower di e holder and its dies while the upper head remains sta-- tionary in the position to which it is adjusted. With the lower-head in a lowered position and the dies separated, the pin 26"will be in its lowered position as'shown in Fig. 4. A pellet 66 of the material of which the cap-is to be formed is then placed in each lower die and these dies raised. Thepellet 63 engages the end piece 262 of the pin 26, forcing the pin 26 upwardly against the action of spring [9 until the end piece 262 1 is seated in the recess 242 of the male die 24. 1 Continued upward movement until the lower dies andthe upper dies engage, as shown in Fig. 5, results in shaping-the material between the dies and the dies are held engaged during whatever period is necessary to set the molded material sufliciently to permit removal of the cap from the dies. When the molded material is sufiiciently I set, the lower die is lowered, leaving the cap 52 threaded on theupper die and ending any danger 1 of apartial vacuum between the lower die and j the cap causing the cap to bulge outwardly. Upon the lower die being dropped, fluid under pressure is supplied to the cylinder 44 to operate the piston therein in a direction such that the f racks 36 operate the gears 28 and the upper dies 24 in a direction to unscrew the dies 24 from the caps 52. As the dies 24 are held against vertical movement and the caps 52 are held against rotation by the projections 264 on pins 26, the rotation of the dies 24 forces the caps 52 downwardly, breaking the seal between the upper dies 24 and the caps 52 and permitting any gas which was formed during the molding operation to escape along the pins26;

The pins 26 being free to move under the pressure of spring [9 are'held against the caps so that the projections 264 prevent rotation of the caps until the dies 24 areunscrewed from the caps and the caps permitted to .drop. Fluid under pressure is then admitted to the cylinder 44 to return the racks 36, gears 28 andupper dies 24 to'their initial positions and fpellets 60 are placed in the lower dies Ii) for the next molding operation.

In the modified construction shown in Fig. 10 the female die I66 secured in the lower die holder I has an opening in which is secured a member llll which projects into the recess of the die I66 so as to form an angular recess in the molded article 52L Rotatably mounted in the bushing in the upper die holder 4 is a die 244 arranged to be rotated by the gear 23 and rack 36 and having a circular projectingportion 245 which closely fits the recess in the die I66 and is interiorly threaded, as at 246, to provide an exterior thread on the molded article 52L The gear 28 and the die 244 have a-lined central openings to receive t8 in the upper die holder 4.

vent rotation thereof.

In the modification shown in Fig. 11, the female die I02 secured in the lower die holder 1 receives the closely fitting annular extension 241 of the die- 248 which is rotatably mounted in the bushing The die 248 is retated by means of the gear 28 and rack 36 and the; extension 241 is interiorly threaded, as at 249, to form an exterior thread on the molded piece 522.

The die 248 has a. central opening in which is mounted a die 256 while the gear 28 and the die 256 have'alined openings in which are mounted the pin 26 and, its tapered end piece 262. As in the-other constructions, the pin 26 is held against rotation by the pin 25 while being permitted" a limited longitudinal movement and the end piece 262 is shapedto interlock with the molded article 522and prevent rotation thereof. v I

In the operation of these constructions, after the article has been molded, the lower plate'and die holder are dropped, withdrawing the 'l'ovver die from the molded article. The rack i then operated to rotate the gear 28 and' the upper die 244 or 248 in a direction to unscrew the die from the molded article. The article is held against rotation by the end piece 262 until it'i's screwed out of the die 244' or 248, the. end piece 262 beingheld in engagement with the article by the spring ['9. When unscrewed from'the die 244 or 248 the article drops from the end piece 262.: The rack is then operated to its original position and the parts are ready for another molding operation.

What is claimed is: 1. In a molding device, a die forzmolding a threaded article, said di'e having a threaded annular rotatably mounted portion'hel'd' against I axial movement and a movable central portion held against rotation, said central portion being shaped to hold the molded article against"rotation, means for rotating said rotatably mounted die portion to remove the molded article from the die and means holding said. central nonrotatable die portion in engagement with the molded article until the molded articlefiis 'removed from the rotatable'die, portion.

2. In a moldingdevice, a; die for molding a threadedarticla said die having anpannular threaded rotatably mounted portion'held; against axial movement and a movable central portion held against rotation, said'central' die portion being shaped to hold the moldedarticle against rotation,. means for rotating. said rotatably mounted die portion to remove saidmolded article from the rotatable. die portion, the molded; article being moved bodily by the rotation of said die portion; and spring means. to. hold said central die portion engaged with the molded article: until said molded article'i's removed from said'rotatable die portion.

3. In a molding device, a male die for molding a threaded article, said'diev having-an. annular threaded portion and. a movable central portion held against rotation, said central die"portion' being shaped. to hold the molded article. against rotation, a gear operatively connected tor said annular die portion, means rotatabl y supporting said gear and annulardie portion and: holding said annular die "portion against axiai'movement,

a longitudinally movable rack bar engaging said gear, means to operate said rack bar and gear to rotate said annular die portion. to remove the molded article from said annular die portion and spring means for holding said central die portion in engagement with the molded article until said article is removed from said annular die portion.

4. In a molding device, a male die for molding a threaded article, said die having an annular threaded portion and a central die portion movably mounted in said annular die portion, said central die portion being held against rotation and shaped to hold the molded article against rotation and said die portions cooperating to control a vent passage through said annular die portion from the space between the article and said annular die portion, means rotatably supporting said annular die portion and holding said annular die portion against axial movement, means for rotating said annular die portion to remove the molded article therefrom and means for moving said central die portion to hold said central die portion engaged with the molded article and to open said vent passage through said annular die portion upon rotation of said annular die portion.

5. In a molding device, a male die for molding a threaded article, said die having an annular threaded portion and a central die portion movably mounted in said annular die portion and cooperating therewith to control a passage through said annular die portion, said central die portion being held against rotation and shaped to hold the molded article against rotat 6 tion, means rotatably supporting said annular die portion and holding said annular die portion against axial movement, means for rotating said annular die portion to remove the molded article therefrom and means for moving said central die portion to hold said central die portion engaged with the molded article and to open said passage through said annular die portion to vent the space between the article and said annular die portion upon rotation of said annular die portion.

6. In a molding device, a male die for molding portion to remove the molded article therefrom,

and means for moving said central die portion to hold said central die portion engagedwith the molded article and to open said passage through said annular die portion to vent the space between the article and said annular die portion upon rotationof said annular die portion.

ERICH GRONEMEYER. 

